Device for tensioning the weft thread in looms



March 18, 1952 E. PFARRWALLER DEVICE FOR TENSIONING THE WEFT THREAD INLOOMS Filed NOV. 20, 1946 4 Sheets-Sheet l INVENTOR:

ERW/N PFARRWALLER BY 4- g4;

ATTOR EY March 18, 1952 E. PFARRWALLER 2,589,429

DEVICE FOR TENSIONING THE WEFT THREAD IN LOOMS Filed Nov. 20, 1946 4Sheets-Sheet 2 Fig.3

I N VEN TOR:

ERW/N PFA RPM/ALLEP BY ATTO EY March 18, 1952 E. PFARRWALLER 2,589,429

DEVICE FOR TENSIONING THE WEFT THREAD IN LO OMS Filed NOV. 20, 1946 4Sheets-Sheet 5 V W 8% g m 'I a Q 1 r X D A L 4.0, a N '0 0% Q0.) Nice 0INVENTOR:

E RW/N PFARRWALLER A TTO EY March 18, 1952 E. PFARRWALLER 2,589,429

DEVICE FOR TENSIONING THE WEFT THREAD IN LOOMS Filed Nov. 20, 1946 4Sheets-Shet 4 INVENTOR. ERWINPFARRWALLER.

ATTORNEK Patented Mar. 18, 1952 DEVICE FOR TENSIONING THE WEFT THREAD INLOOMS Erwin Pfarrwaller, Winterthur, Switzerland, as-

signor to Sulzer Freres, Societe Anonyme, Win.-

terthur, Switzerland Application November 20, 1946, Serial No, 711,109In Switzerland November 24, 1945 The present invention relates to amethod and means for tensioning the weft thread in a loom.

Among the objects of the invention are to tension yarn or thread in agripper shuttle loom in order to give the desired quality orcharacteristic to the finished cloth, to accomplish the ten- Sioningreliably at relatively high speed and in coordination with theoperations performed by other parts of the loom mechanism, to presenttensioned yarn for the beat-up operation, and to control weft-tensionand draw off yarn from the bobbin simultaneously. In carrying out themethod, so much of the weft thread is pulled bacl; at the inlet side ofthe shed that not only is the desired thread tension obtained, but alsoY weft thread is drawn off from the supply bobbin. The method may becarried out by means of a pull-back device arranged at the inlet side ofthe shed, this device being controlled by the loom drive in such a waythat weft thread material is not only drawn back from the shed, but alsodrawn from the bobbin, j r

Further and other objects of the present invention will be hereinafterset forth in the accompanyin specification and claims and shown Fig.3is' a top view of the detail shown in Fig. 2;

Figs. 4 and 5 are part-sectional side views of another detail of themechanism according to the invention.

Fig. 6 is a diagrammatic illustration of a mechanism forming plat of thesystem shown in Fig.4.

In performing the method in accordance with a preferred form thereof, ona loom of the gripper shuttle type, a source of Weft thread materialsuch as a bobbin I is provided outside of the shed. As shownschematically in Fig. l, the bobbill I is arranged at the picking side Aof. the

10 which is entry side of the shed m. The

end I3 oi the thread is projected through the shed It to the receivingside 13. In order that 18 Claims. (Cl. 139-126) the end It may beprojected readily through the shed III, a loop is formed in the portionof the thread between the bobbin I and the end I8 be: fore the .end I3is projected through the shed. This loop is represented in diagram I ofFig. l by a portion of the thread extending to the point 51). As the endI8 is projected to thepoint I841, as shownfin-diagram II, the loop istaken up and additional thread is drawn from the 0011? bin I.

If a shuttle such as a gripper shuttle 9 is emf ployed for projectingthe thread end l8 through the shed it, there tends to be some overshoot,which is irregular. For the sake of uniformity, the end. it is broughtback to a fixed point shown at Ifib in the diagram III. Theresultingslacl; is taken up by forming a small loop and drawing thethread back to the point 50,. The thread is 'then'gripped by a holdingand positioning .de-. vice 2 at the entry side of the shed I0 and soy-.-ered at the point 22, by a cutting device where:

upon the weft thread is beaten into the shed while it is still undertension, the cut ends having been held. The shed is then closed and anew shed is formed. The thread end 22 is then returned to the point 22abysaid holding and positioning device and attached to a new shuttle andreleased by said holding device preparatory to being projected againthrough the next shed. Inreturn the thread end 22 to the point 22a, thesize of the loop in the portion of the shed between the bobbin I and theend 22a is increased by drawing the thread back to the point 5?), shownin diagram V of Fig. l. The increase in size of the loop is such thatnot only is the distance 23 between the points 22 and 22a taken up, butadditional material is also drawn from the bobbin I in forming the loopof increased size.

The loop to the point 52) is preferably released at the same rate as theend I8 is drawn out ior projection through the shed I9 so that noslackness the thread is permitted to develop. Preferably, after thematerial of the loop has been taken up in projecting the shuttle 9 withthe thread end I8 through the shed I0, sufficient braking is applied tothe thread drawn from the bobbin i to maintain the same tension.

The mechanism shown in Fig. 1 includes in addition to the bobbin 5, aguide eye 3, a first thread brake i, a thread pull-back 5, and a secondthread brake E. Beyond the brake 6 is a further guide eye I followed bya shuttle-feedin thread 2 While it is being inserted into the shed III.The holding and positioning device 8 may be constructed according toFigs. 1 to 4 of the U. S. Patent No. 2,163,760 to A. Moessinger. On thepin It is mounted the picking stick I I, which is shown in detail inFig. 4 and is operatively connected with the loom drive; by means ofthis stick the shuttle 9 is picked through the shed I and moves past thethread cutter I2 and past the thread clamp I3 before entering the shedI0. At the shuttle receivin side B of the loom the shuttle 9 passesanother thread clamp I5 before it enters the shuttle brake l6, where itcomes to rest in position 9a.

Since it is difficult to bring the shuttle 9 which arrives at greatspeed at the side B, exactly into the position which corresponds to theposition ofthe weft thread 2 before it is beaten into the fabric, theshuttle 9 is permitted to move beyond the ultimate position of the endof the weft thread by a distance 2I which is not necessarily constant.The shuttle 9 is then pushed back into its proper end position 9b,within the shuttle brake, by means of a pushing device I"! which may becoupled to the loom drive as shown in Fig. 5. 'After the shuttle 9 hasreleased the weft threadZ when in its end position 917, it is broughtout of the picking path into a position 90 and then carried back intothe position M, from where it comes again into the picking path toeffect another insertion of the weft thread 2 into the shed I9. Forefiecting the aforedescribed movements of the shuttle a mechanism may beused as disclosed in United States Patent NO. 2,420,380 of May 13, 1947.

The operation of the parts described so far is as follows: e

The thread brakes 3 and 6 are opened when the shuttle 9 is picked intothe shed ID. The thread pull-back device 5 is in its extremeoutside-position 511 while the thread 2 takes up the position indicatedby I in Fig. l. The end I8 of the Weft thread 2 is firmly gripped by theshuttle 9. When the shuttle is picked by means of picker II the threadpull-back device 5 begins to move inward in the direction of the arrowI9. The picker II and the thread pull-back device 5 are operativelyinterconnected andthe back swinging motion of the thread pull-backdevice is effected in dependence on the time of the pick or on thepicking speed of the shuttle by a mechanism, for example as shown inFigs. 2 and 3.

The inward-movement of the thread pull-back device 5 may be of such anextent that the .reserve length of weft thread released therebycorresponds approximately to the first part of travel of the shuttle 9which is only a fraction' of the total length of an inserted weftthread. In order to ensure coordination of the inward-movement of thethread pull back device and of the picking movement or of the pickingspeed of the at the moment when the thread pull-back device 5 hasarrived in the axis of thepicking path of the shuttle 9; because ofthis, the weft thread 2, drawn from the bobbin I while being insertedinto the shed It], does not deviate from the straight path, or deviatesonly slightly. As soon as the shuttle 9 arrives at the receiving side Bin the shuttle brake IB and before its speed is slowed down, at leastone of the thread brakes 4, 6. comes into operation to prevent thekinetic energy of the moving weft thread 2 from causing a superfluousamount of thread to be drawn from the bobbin I, which would result inthe weft thread running loose inside the shed I0 and forming loops andwaves.

When the shuttle 9 comes to rest in the position 9a, the weft thread 2is in the extended position 2a shown in II in Fig. 1. The threadpullback device 5, operated for instance by the means shown in Figs. 2and 3, moves in the direction of the arrow 29, whilst at the same time,with the thread brake 4 closed, the pushing device I! transfers theshuttle 9 into position 91) and the end of the weft thread 2 fromposition I8a to I8b as shown in II and III in Fig. 1. The movement ofthe pushing device I! which is caused for instance by the means shown inFig. 5, and the outward movement of the thread pull-back device 5 whichmay be effected by the mechanism illustrated in Figs. 2 and 3, arecoordinated and not only is the thread pull-back device 5 pushed outwardby a distance necessary for tightening the weft thread 2 when the weftthread end is moved back from position l8a to I81), but also more weftthread material is drawn from the stock, i. e. from the bobbin I throughthe brake 4.

The extent of push-back movement of pusher I1 and of swing-out movementof thread pullback device 5 are so coordinated that the former issmaller than the length of thread pulled out by device 5 minus theclearance between the two brakes 4 and 6. Start and completion of bothmovements may coincide. However, the grooved member 'I'I shown in Fig. 5which will be described later, may be set so in relation to the settingof cam 21 in Fig. 2 that the pull-back device 5 is actuated beforeactuation of pushback member I I. Members II and 2'! are both driven bythe main shaft of the loom. With this adjustment the thread puller 5pulls some thread from the supply I before. it pulls thread back fromthe shed and tensions it in coordination with the pusher I1. Relativeoperation of pusher I! and puller 5 may be so adjusted that both beginto operate at the same time but that, after the thread end has movedfrom position IBa to position 58?), Fig. 1, and the thread puller .5 hasmoved fro-m position 5 in operating step II to position 5a" in step III,the stroke of puller 5 is not yet completed and that completion of thestroke causes not only tensioning of the weft thread but also pulling ofthread from its source of supply. The shuttle brake I6 prevents pullingOf the thread end I8, which is held by the shuttle, beyond point I8b.

The tension of the thread 2 in the positions 2a and 2b in Fig. 1 dependson the setting of the brake t. However, with a more powerful action 1 ofbrake 4, the tension in the weft thread 2 is greater, and with a weakerbrakin action itis less. In the position 2b shown in'III in Fig. 1,

' the weft thread 2, adjustably tightened, is 1 gripped by the two edgegrippers I3 and I5 and taining the tension given to it with-the help ofthe,

braked. Through this control of the tension of the weft thread to bebeaten up into the fabrie,.

th'equality of the fabric can be influenced greatly and suited to theuse. for which it isintended.

3 Thedevice 8, which was moved into position- Ba'by means, for instanceas shown in Fig. 4 and operated by the loom drive, returns the new end22 of theweft thread 2 by the length 23 to p sition' 22a, whilst at thesame time the thread pull-back device moves from position 5a in thedirection of the arrow 20 into the position 52), as illustrated in IVand V in Fig. 1. The speed at which the device 8 moves back from theposition 8a into the initial position and the speed at which the threadpull-back device 5 moves from 50. to 5b, are coordinated and in thisphase of operation not only is the weft thread 2 securely held undertension by the brake 4 and the device 8,'but also additional weft threadmaterialis drawn from the bobbin I through the closed brake 4 whichretards the movement of the thread but does not stop it.

Thereby, also in this phase of operation, illustrated by IV and V inFig. 1, a tension in the weft thread is created and maintained which isdependent on the setting of the brake 4. As soon as the end of weftthread 2, which is drawn back from shed H] and away from brake 4, ar-

during the pick, a supply of loose thread is made available facilitatingacceleration of the shuttle and preventing jerks on the thread runningoff the bobbin.

The described method not only prevents any wear on the thread in theweaving operation, but the-thread is also better protected and theduality of the fabric can be controlled. The braking of the weft thread2, with the shuttle 9 in the receiving brake l6 and at the return motionof the weft thread 2, may be effected by brake 4 alone which is arrangedbetween the bobbin l and the thread pull-back device 5, or by the twobrakes 4 and 6. If two brakes are used, they may be coordinated withrespect to the time at whichthey operate and to the intensity of theiroperation.

As shown in Figs. 2 and 3, the thread pullback device 5,diagrammatically illustrated in Fig. 1, may be provided with a one-armswinging lever '24 which is pivoted on a stationary pin 25. The free endof the lever 24 is fitted with a hook 25, through which the weft thread2 passes. A cam follower 29 is rotatably mounted on the lever 24 by apin 38. This cam follower cooperates with a cam 21, which is fixed onthe shaft 28 of the loom drive. A piston rod 33 is pivotally attached tothe lever 24 and extends into a cylinder 35. A piston 3lis fixed to rod33 within cylinder 35 and loaded by a pressure spring 32 resting on anadjusting screw in the cover of the cylinder. In the lower part of thecylinder 35 aybcre 34 is provided which is covered by ,the piston '31when the latter approaches its lowest end position.'- v r Movement ofthe pull-back device 24, 26 in the direction of'the'arrow 20 to theextreme outward position 2411, shown in dash-dot lines, is efiectedby'the cam 27 against the action of the spring 32.

which is tensioned by the piston 31 moving to ward its upper endposition. The run' ofi side, 21d of the cam 21 is so steep, i.e..radial, that the:

inward movement of the pull-back device 24', '26 in the direction of thearrow I9 is efiected solely under the action of the spring 32' and'riisindependent of the speed of the drive shaft- 28 and therefore alsoindependent of the speed of- .the. loom drive. I 1

Since not only the speed of the movinginmotion of the thread puller 24but also the picking speed of shuttle 9 are independent of the speed ofrotation of the loom drive, the former speed may be coordinated to theinitial picking speed of the shuttle by proper adjustment of the initialtension of spring 32, Fig. 2,'and spring 88, Fig. 4,. to be describedlater, and the length of thread pulled by the shuttle at the beginningof the pick is provided by the moving-in motion of the thread pullerwithout withdrawal of thread (rom the supply 1.

Shortly before the pull-back device 23, 25

reaches its initial position, whereby the weft.

(Fig. 1), the movement of the pull-back device- 24, 26 is pneumaticallyretarded, the piston 31 covering the bore 34, whereby the air under thepiston 3| can escape only slowly or not at all, and is thereforecompressed.

Return motion of the pull-back device 24', 26 into the initial positionby a force whose magnitude is independent of the loom drive, such as asprin s, is particularly recommended when the shuttle 9 is picked by aforce whose magnitude is also independent of the loom drive, for exampleby the use of a picking device as shown in 4". On the other hand, if thepick of the shuttle' is'effectedby means of a cam operated'bythe loomdrive, it ispreferable to control the weft release movement of thepull-back device, i. e; movement of lever 24, 25 from the extremeoutwardposition 24a into the initial position; by a or an eccentric driveinstead of b spring 32-1 The brakes 4', 6 shown diagrammatically in 1have each a brake arm 35 as shown inj'Figs. 2 and 3 which is pivoted onthe fixed-pin 3! and provided with a tension spring '48. On eachbrakearm 35 a brake shoe 38 is arranged which is" pressed under the action ofthe tension spring 45! to a soft body which is held taut, for instancetothe braking belts and the brake shoe 3B." The endlessbraking belts 39ext nd around a driving roller 48 and a tension roller lll. The twodriving rollers M! are fixed on asha t 42 provided with a ratchet wheel43 into which fits a'pawl 44. The pawl is conne ted to a tipping lever46' by means of pm 4'5: the tipping lever is pivotably mount ed onstationary pin 41. The tipping lever 46 and the swinging lever 24 arepivotably connected to the operating rod 69. Each swinging motion 7 ofthe lever 24 causes a rotary motion of the driving roller 48, wherebythe brake belts 39 are intermittently moved relatively to the brakeshoes 38 In this way concentration of wear at a single point of thebraking belts 39 by the weft thread 2 Each fork 5i is "under the actionof a tension.

spring 53 whose pullcan be adjusted-by r'ne'a'ns of screws 5d forsetting'the'tension-ofthe'brak belts ligand consequentlythe'brakiri-gaction on theweft thread 2. I i w e In each of the two brake arms 36 acam fol lower 55- isfitted by means of a pin 38' and is pressedzagainsta cam. 55 by the action of the springs 48. The two cams 55 are fixed onthe shaft vL28 of the loom drive. The motion of the brakeshoen 38 andtheoutward motion of the pull-backjzdevice 24, 26 in the direction ofthe arrow 28' are dependent on the motion of the cams'i55 and 21respectively and are thereby de pendent on the speed of the loom drive.The timingof the motions of the pull-back device 24, 26 and" of thebrake arms 36 with respect to each otherris determined by theqrelativeposition of the cams 21 and 55 and may be changed by alteringtheirrelative positions. With this arrangement-it is not only possible toadjust the brake force-acting on the weft thread by suitably increasingordiminishing the tension in the brakingi.belts'39, but also to adjustthese brake pressures "within each operatingcycle by suitably shapingthe cams 55 and setting their relative .as 'well as adjustment andmaintenance of the tension when the weft thread 2 is beaten up into thefabric. I

.Fig. 4 illustrates the positioning device 8, which, asshowndiagrammatically in Fig. 1, transfers the weft thread end 22 fromposition IV to position-;V (22a). Device 8 is held by a guide piece 51which is slidably supported between the guides 59 arranged on two sidesof the shuttle 9. The guide piece 51- is connected to a driving lever 6|pivoted on'the fixed pinBO by a link member 58. At one end of the lever6| a cam follower 62 is arranged runningin cam groove 63 of a controlcylinder-64. The control cylinder 84 is mounted on the shaft- 28 of theloom drive. By suitably shaping of" cam groove 83 and a relativeproportioning of the length of the arms of the lever 6|, the movement ofdevice 8 may be made to that the stroke of member 5 (26) is not yetcom-- pleted when that of device 8 is completed, or that member 5 beginsto move before device 8'has brought the thread end 22 into the position22a. Duration of action of both motions may be the same.

Fig. 6 is a diagrammatic illustration of a weft thread gripping andpositioning device as may be used in the mechanism according to thepresent invention. One the left side of Fig. 6, the device isshown inthe position shown on top of Fig. '1 and designated by 22a at the bottomof said figure. 7 In this position the grippers 9 of shuttle'9 have justbeen closed on the thread 2 and the thread is still held by the grippers8 of the positioning member 51. Up-strokev of rod 88'preliminarily tothe release of the shuttlepicking means causes clockwise movement of thegripper- .openin'g lever 8'-as indicated by arrows in Fig. 6.

When this lever reaches a position at rightangle to the longitudinalaxisof the grippers, the; lat- This is acter are opened and permit theshuttle to move to the right trailing a weft thread. Member 51- is thenalso moved to the right to the position and in the condition shown onthe right side of Fig. 6, i. e. with the grippers open. When the;

pick is completed, the thread cutter l2 comes into action and closes thegrippers 8 prior to severing the thread. Downward movement of a cuttingmember 12 causes member 8 to be turned counter-clockwise as indicated byarrows on the right side of Fig. 6. After the thread has been cut,v

' the shuttle is moved into the channel to assume the position in whichit is shown in *Fig; 6. The. pin is withdrawn for closing clamps 9' uponthe;

thread 2. The mechanisms shown in Fig. 6 are conventional and areillustrated only because such mechanisms are suitable for use in amechanism according to the invention.

The. picker II is pivoted on the shaft l4 and. provided-with an arm 12which .is joined to a link 13, Through the joint 15 the link 13 isconnected to a second link 14, which is pivoted on a stationary pin 16.A tensioning lever I1 swings about a pin '18 and is fulcrumed at its end19 to a pushrod 88. The push rod 80 has at its free end a cam follower8| which is pressed to a cam 83 by means of tension spring 82 attachedto the push rod 80; the cam 83 is fixed on shaft 28 of the loom drive. 4Push rod 88 is provided with anabutment 89. This cooperates with one armof bell-crank lever 84, whose second arm acts on the joint pin 75. Astrong tension spring 88 acts on .the picker I]; it imparts thenecessary acceleration to the picker I I when picking.

In Fig. 4 the position is shown which the picking device takes upshortly before the shuttle '9 is picked. If now,the shaft 28 of the loomdrive rotates, the push rod 80, due to the pulling action of the spring82, moves upwards to follow a corresponding movement of the cam 83. Thestop 88 presses on the bell crank lever 84; the movement of whichpresses the lever pair 13, 14 into its extended position and then in thediIQO-r tion of the arrow 86 into flexed position whereby spring 88 isreleased and the picker l I accelerated in the directionof the arrow 81.The shuttle 9 is moved there-by at great speed between the open threadcutters l2 and past the thread gripper is into the shed I 8, whilst thepicker ll comes torest in the positionllabecause of a stop 90. The cam83 then presses the push rod 88 down against the action of. springs 82and 88,;

whereby the tensioning lever 11 is swivelled into position we and thespring 88 is tensioned. This causes not only straightening of the linkpair 73, 14 but also imparts sufficient kinetic energy to cause it tocome to rest on a stop 85 in aposition slightly flexed toward lever 84.Further rotation of the cam 83 permits push rod to be moved upward bythe spring 82 into the intermediate position shown in the drawingwhereby the tensioning lever 11 is swivelled out of the path of motionof the picker l i and the latter remains locked in the position readyfor the pick. Further upward moving oiv the push. rod 80 caused by thespring 82 and the position of the cam 83 initiates the next pick. f

In the same manner as the device 8 in Fig. 4 the pushing device 17,shown in Fig. 5, can be actuated from the shaft 28 of the loom drive.

anew

. 9 The pushing device I! moves the shuttle S from its ultimate position90; back to position -9b. The pusher member I! travels in a guide 65. Tothe pushing device I! a link member 66 is jointed which is connected toan operating lever 61. The

operating lever 67 is supported by a pin 68 and has at its free end acam follower B9. The latter fits into a cam groove in a control cylinderII. This control cylinder II is fixed on the shaft 28 of the loom drive.As in the case'of the drive shown in Fig. 4 the shape of the cam groove10 and the ratio between the length of the two arms of the lever 67 maybe chosen in such a way, that in spite'of thefweft thread moving fromposition II to position III (Fig l') in addition to the length ofthread: needed for tighteningthe weft thread, alsosom'e weft threadmaterial is drawn off from the bobbin I by the thread pull-back deviceii. a 7

While I believe the above described, embodiments of my invention to bepreferred embodiments, I wish it tobe understood that I do not desire tobe limited to the exact details'of design and construction shown .anddescribed, for obvious modifications will occur to a person skilled,

inthe art.

I claim:

1'. In a loom for weaving, the combination of drive means, a stationarysource of weft'thr'ead supply, a shuttle, two positivelyactuated weftthread retarding means, weft thread pull-back means disposed betweensaid retarding means and moving substantially reciprocatin'gly andtransversely to the line connecting'said retarding 2. In a weavingloomof the typeha'ving aweft.

thread bobbin, a shuttle movable substantially in a line away from thebobbin for carrying .7 thread through a shed, and a loom drive shaft,

the combination comprising a thread'pull-back lever between the bobbinand the'shed having a hook. through which thread is adapted to pass, acam on said drive shaft engaging said lever for oscillating the leversynchronously withdrive shaft rotation-in a plane transverse to the lineof motion ofthe shuttle, a weft-thread brake between the bobbin and thepull-backlever, having a brake surface and a movable brake shoe beatween which thread may pass, and a cam on'said drive shaft engaging saidbrake shoe for oscillatmg said brake shoe synchronously with said driveshaft rotation, said brake being so located relativetothe thread hook ofthe said pull-back lever that the brake forms a guide for the thread.causing the thread to form a. loop while said hook moves away from thel-ine'ofmotion-of; the

shuttle. .7

3. In aweaving loom of the type having a weft thread-bobbin, a grippershuttle movable substantially in a line away from the bobbin for Icarrying thread through a;shed,,and aloom drive shaft, the combinationcomprising cam means on the shaft, a shuttle-feeding-Weft thread gripperdisposed between said bobbinand the shed .and guided to move inthe lineof movementof the shuttle and having operating mechanism driven by saidcam means, said mechanism serving to translate rotary motion of theshaft into reciprocating movement of the said" gripper'jtoward and fromthe shed, a'thread pull back lever between the bobbin and theweft-thread shuttle-feeding grippenhaving a part through which thread isadapted to pass, and a cam on said drive shaft engaging said lever foroscillatin'g, thelever synchronously with drive shaft rotation in'a'plane transverse to the lineof motion of the shuttle, said cams being solocated on said shaft that the part of the said pullback lever, throughwhich the thread passes,

1 moves away from the line'of motion .of the shuttle while'the'saidgripper holds the thread and moves it away from the'sh ed'.

4. In a weaving loom of the type having a -loom drive; shaft, a weftthread'bobbin, and a shuttle movable substantially in a line away fr8mthe bobbin for carrying thread through ashed, the combination comprisinga shuttle picker at the side of the shed near the bobbin, actuatingmechanism for the shuttle picker, a cam on said drive shaft engagingsaid picker actuating mechanism,

a shuttle push-back lever at the far side of the shed, a cam. on saiddrive shaft engaging said lever for moving the-shuttle back to a fixedposition froman overshot position, a thread-pullback lever between thebobbin and the nearsid-e of the shed having a hook through whichthreadis'adapted to pass, a cam on said drive-shaft engaging saidpull-backlever for oscillating the lever synchronously with drive shaftrotation in a plane transverse to the direction of motion ofthe'shuttl'e, a weft-thread brake between the bobbin and the pull-backlever, having 'a brake surface and movable brake shoe between whichthread may pass, and a cam on said drive'shaft engaging said brake shoefor oscillating said brake shoe synchronously with'said drive shaft,

said cams being so located that the thread hook of the said pull-backlever moves away from the line of motion of the shuttle as theshuttle-push backflever moves the shuttle at the farside of the shed toits fixed position, andwhile thethread brake shoeis moved to the brakesurface-for retarding run-off of weft thread from the bobbin while saidhook pulls on the thread for taking up the slack caused bytheback-movement ofthe shuttle, without stopping said run-off.

5. In a loom for weavin the combination of loom drive means, a source ofWeft thread. supply,

warp threads forming a shed, a weft thread pull back mechanism disposedat the side of the shed where the weft thread enters it when beinginserted and including, a cam rotated by said loom drive, a lever havingan end portion adapted to engage a weft thread, a cam follower mountedon said lever and engaging said-cam, and spring means holding said camfollower to said cam, the pulling of the weft thread being, effected in,positive-relation to the configuration of the cam.

6; Ina loom for weaving a weft thread pull back mechanism as defined inclaim 5-,v said- 0am I being so formed as to positively move said'leverin a direction forpulling the weft thread and to afford return movementof said'lever toinactive position by means of said spring. 1

7 In a gripper shuttle loom having loom drive means, a source of weftthread supply, and warp threads forming a shed, the combination of-qaweft"; thread pull back device disposed at the; side pf the-shed wherethe weft thread enters it when completion of the pick.

exclusively in the line of the weft thread enter- W ing the shed anddisposed at the same side of .the shed as said pull back device and alsoconnected to and driven by said loom drive to move reciprocatingly atinterdependent timing with said pull back device.

' 8. In a loom for weaving, the combination of loom drive means, ashuttle, a shuttle picking mechanism comprising resilient meansperiodically tensioned by said drive means and released and pickingthereby the shuttle with an accelerating force independent of said drivemeans, a Weft thread pull-back mechanism comprising actuating meansconnected to and operated by said loom drive means and comprising otherresilient means tensioned upon actuation of said pull-back mechanismbysaid actuating means and released and returning thereby said pull-backmechanism to inactive position by a force independent of said drivemeans, and individual adjusting means connected individually with saidresilient means and controlling their tension.

9. In a loom for weaving, the combination of loom drive means, ashuttle, a shuttle picking mechanism comprising resilient meansperiodically tensioned by said drive means and released and therebypicking the shuttle with an accelerating force independent of said drivemeans, and a weft thread pull-back mechanism comprising actuating meansconnected to and operated by said loom drive means and comprising otherremeans, weft thread motion retarding means, said three last mentionedmeans individually comprising actuating means connectedwith and actuatedby said drive "means and operated at interdependent timing, saidactuating means being so constructed as to release said retarding meansat'the start of the pick and to apply same before completion of thepick.

11. In a lo'om' for weaving, the combination of drive means, astationary source of weft .thread three last mentioned meansindividually comprising actuating means connected with and actuated bysaid drive means and operated at interdependent timing and being adaptedto release said retarding means at the start of the pick and to applysame substantially simultaneously with the 12. In a loom for weavinghaving loom drive means, a source of weft thread supply, warp threadsforming a'shed, the combination of a "and simultaneous withdrawal ofweft thread from said source.

'13. In a loom for weaving having loom drive means, a source of weftthread supply, warp threads forming a shed, the combination of a weftthread pull-back device and a weft thread motion retarding device, bothdevices being disposed and acting on the weft thread between said source'and the side of the shed where the weft enters when being inserted, amechanism connected to and driven by said drive means and connected toand positively actuating both said devices at interdependent timing,said retarding device comprising two clamping means spaced along theline of movement of the weft thread toward the shed and engaging thethread, and said pull-back device having a member disposed between saidmeans and movable transversely to the line of movement of the threadtoward the shed for pulling the thread to form substantially a trianglewhen said member is moved from said line of movement, the corners of thetriangle being formed by flexing the thread at said means and atsaidmember.

14. In a weaving 100m having warp threads forming'a shed, a source ofweft thread supply disposedoutside the shed, a shuttle transporting weftthread from said source through the shed,

. and a loom drive, the combination comprising a weft threadpull-backdevice disposed between said source and one side of the shedand engaging the weft thread and being adapted to pull weft thread fromthe shed and also from said source, a shuttle push-back device disposedon the other side of the shed for pushing the shuttle from anovershotposition back to a fixed position, actuating means individuallyconnected with said pull-back and with said push-back depositioningmeans disposed between said pullsupply, picking means, weft threadpull-back 'means, weft thread motion retarding means, said weft threadpullback device and a weft thread motion retarding device, both devicesbeing disposed and acting on the weft thread between said source'and theside of the shed where the weft enters when being inserted, anda-mechanism connected to and driven by said drive means and connected toand positively actuating both said devices at interdependent timing'andbeing so constructed as to afford withdrawalfof weft thread in adirection away from the shed back device and the shed, weft threadsevering means disposed between said positioning means and the shed andsevering the weft thread after it has been gripped by said gripping'andpositioning means, actuating means connected with said positioning meansand the loom drive and moving said positioning means witha grippedshaft, the combination comprising cam means on the shaft, ashuttle-feeding weft-thread gripper disposed between said bobbin and theshed and guided to move in the 'line of motion-of the shuttle and having.an operatin mechanism' driven by said cam means, said mechanism servingto translate rotary motion of 'the shaft into reciprocating movement ofthe said gripper toward and from the shed, a thread pull-back leverbetween the bobbin and the weft-thread shuttlefeeding gripper, having apart through which thread is adapted to pass, and a cam on said driveshaft engaging said lever for oscillating the lever synchronously withdrive shaft rotation in a plane transverse to the line of motion of theshuttle, a weft-thread brake between the bobbin and the pull-back leverhaving a brake surface and a movable brake shoe between which thread maypass, and a cam on said drive shaft engaging said brake shoe foroscillating said brake shoe synchronously with said drive shaft, saidcams being so located on said shaft that the part of the said pull-backlever, through which the thread passes, moves away from the line ofmotion of the shuttle while the said gripper holds the thread and movesit away from the shed and said brake affords simultaneous pulling ofthread from the bobbin.

17. In a loom for weaving having warp threads forming a shed, a sourceof weft thread supply disposed outside of the shed, loom drive means,and gripper shuttles, the combination of picking means for saidshuttles, a weft thread pull-back device, weft thread cutting means, anda weft thread holding and positioning device guided to move in the lineof movement of said shuttles, said devices being connected with andinterdependently operated by said drive means, said holding andpositioning device being adapted to move the end of a weft thread fromthe shed toward said source after it has been out by the cutting meansafter the pick and said pull-back device being adapted to pull back themoved weft thread and to pull an additional length of weft thread fromsaid source.

18. In a loom for weaving, the combination of weft threads forming ashed, a source of weft thread supply disposed outside of the shed, loomdrive means, picking means, a weft thread pullback device, weft threadcutting means, a weft thread holding and positioning device, andactuating means interconnecting said devices and said drive means forinterdependent operation thereof and bein adapted to actuate saidholding and positioning device to move the end of a weft thread from theshed toward said source after it hasbeen cut by said cutting means afterthe pick and to actuate said pull-back device to pull back the movedweft thread and to simultaneously pull an additional length of weftthread from said source.

ERWIN PFARRWALLER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 375,335 Bowker Dec. 27, 1887448,202 Bowker Mar. 17, 1891 805,751 Renger Nov. 28, 1905 1,923,954Rossmann Aug. 22, 1933 2,089,620 Rossmann Aug. 10, 1937 2,160,339Moessinger May 30, 1939 2,163,760 Moessinger June 27, 1939 2,407,773Fletcher Sept. 17, 1946 2,420,330 Moessinger May 1 3, 1947 FOREIGNPATENTS Number Country Date 369,694 Great Britain Mar. 31, 1932 449,557Great Britain June 30, 1936 678,468 Germany July 15, 1939 703,304 FranceFeb. 3, 1931 790,166 France Sept. 2, 1935

